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NEW YORK STATE MUSEUM 



than there is ibetween the latter and the skull of Somateria 

 v . nigra. Among the geese, as a rule, the mandibles, although 

 having very much the same shape as we find them in N e 1 1 a , 

 are relatively as well as actually shorter (proportionately) and less 

 wide, depending upon the size of the species of goose. On the other 

 hand, the cranial capacity of the Anserinae is comparatively larger 

 than it is among ordinary Anatinae, and the superior interorbital 

 space is wider, as are also the descending processes of the lacrymal 

 bones in the anteroposterior direction. If we take the characters 

 at the base of the skull in N e 1 1 a r u f i n a, and compare them, 

 character by character, with the corresponding ones at the base of 

 the skull of a specimen of Branta canadensis, we will at 

 once discover that they are essentially repeated in the latter, and 

 that in every detail. In A n s e r a 1 b i f r o n s and in Chen h . 



nivalis we find the inferior surface of 

 the superior mandible powerfully marked 

 with either ridges, or as in the latter with 

 a laterolong-itudinal row upon either side 

 of raised osseous tubercles, corresponding 

 with the elevations and depressions occur- 

 ring in the horny theca which during life 

 cover the roof of this, the anterior part of 

 the mouth. Geese of the genera we are 

 fig. 34 Posterior view of skull examining, have all the bones of the skull 



of Branta canadensis . 



hutchinsii; mandible re- somewhat thickened, strong and dense; 

 moved. Natural size. Same markedly more so than we find the skulls 



specimen as figure 33 et seq. 



of ordinary American Anatinae to be. 

 They are all typically desmognathous. The characters of the skull 

 as they are seen among the smaller of our American geese are well 

 exemplified in Branta c . hutchinsii. 



I present four figures of a skull of this species, giving the four 

 principal views the size of nature. Viewing it from the side, we 

 find a superior osseous mandible of the form practically agreeing 

 with, but much shorter than in, ducks and geese generally. We 

 note here also that a partial septum narium is present, which is 

 absent in Mergus and not a constant character among the others. 



The lacrymal has the broad descending process, but not so enor- 

 mously expanded as we find it in the swans and in Clangula. 

 It will also be noted how this tends to approach the sphenotic process 

 of the opposite side of the orbit, which, in Clangula, it nearly 

 succeeds in meeting. 



